Telomeric repeat amplification protocol (TRAP) assay. (A) Telomerase activity products of human heart-derived (hH1, hH2, and hH3), liver-derived (hL1, hL2, and hL3), and bone marrow–derived (hBM1, hBM2, and hBM3) multipotent cells display 6-bp periodicity. Cells treated with RNase (-i) were used as negative control. TSR8 lane represents the telomerase quantitation control template. Developed autoradiographic film was acquired by SnapScan 1236 (Agfa, Mortsel, Belgium) connected to a Macintosh G3 Computer (Apple, Cupertino, CA) equipped with ScanWise software (v1.2.1; Agfa). (B) Quantitation of multipotent cell line telomerase activity. Each unit of total product generated (TPG) corresponds to the number of TS primers (in 1 × 10−3 amole or 600 molecules) extended with at least 4 telomeric repeats by telomerase. Results are presented as mean and standard deviation. The differences among cell lines did not reach statistical significance.
